Movable wall panel

ABSTRACT

A movable wall panel is provided with an automatic compensating system for ceiling deflections comprising a nestable top panel casing or section spring-mounted within and projecting above an upper body compartment or recess, which top casing in conjunction with an overhead trolley support system and with linked dual jacks which operate to extend a bottom closure panel casing from a lower body compartment enable the panel to maintain a good seal against the ceiling even when the ceiling is subjected to substantial deflections of either a static type or of a temporary dynamic nature. In certain embodiments, the trolley hanger studs are of a fail-safe type having an internal safety cable extending through a bore running the entire length of the stud.

United States Patent Kaufman Mar. 26, 1974 MOVABLE WALL PANEL 3,295,257 1/1967 Douglass 160/40 x 4 S 4 203 [75] Inventor: Arne M. Kaufman, Plainview, NY. 29 072 2/1969 ammons 9/ [73] Assignee: industrial Acoustics Company, Inc., Primary Examiner-Dennis L. Taylor Bronx, NY. Attorney, Agent, or Firm-Morgan, Finnegan, Durham 22 Filed: Aug. 31, 1972 & pm

[21] Appl. No.: 285,345 [57] ABSTRACT A movable wall panel is provided with an automatic U-S. compensating system for ceiling deflections compris- 199 ing a nestable top panel casing or section spring- {51} Int. Cl Ed /26 o t d ithin and rojecting above an upper body Fleld of Search compartment or recess top casing in conjunc- 1 206 tion with an overhead trolley support system and with linked dual jacks which operate to extend a bottom References Cited closure panel casing from a lower body compartment UNITED STATES PATENTS enable the panel to maintain a good seal against the 3,253,552 5/1966 Stein 160/40 x ceiling even when the Ceiling is Subjected to Substan- 3'635123 3/1972 Shuwood 49/127 tial deflections of either a static type or of a temporary 2,151,294 3/1939 El1ingsen..... /1 F X dynamic nature. In certain embodiments, the trolley 1,018,741 2/1912 Davis 85/1 T hanger studs are of a fail-safe typehaving an internal 3,0 2, H1963 Burmeister 49/409 X safety cable extending through a bore running the en- 3,073,38l 1/1963 Burmeister. /40 tire l h f the stud 3.172,166 3/1965 lmbrecht 160/40 UX 3,195,192 7/1965 Neisewander 160/40 X 6 Claims, 5 Drawing Figures PATENTED HAR26 I974 SHEET 1 BF 3 PATENTEDMARZB i974 sum 2 11$ 3 rlIil M L. IIWII FIG. 2

MOVABLE WALL PANEL CROSS-REFERENCE TO RELATED APPLICATION The safety stud described herein is disclosed and claimed per se in my concurrently filed application Ser. No. 285,347.

BACKGROUND OF THE INVENTION Field of the Invention This invention relates to an improved movable wall panel provided with self-compensating means to obtain better sealing against fixed parts of a building structure, particularly in coping with dynamic and static variations in ceiling height. Better and safer handling and installation characteristics for engagement with similar panels are also obtained.

Prior Art Numerous sliding doors and movable panels have been devised to facilitate the dividing of large floor areas into smaller areas for individual exhibits or into booths in gymnasiums, exhibition or convention halls. Various supporting and guiding devices for individual panels have been employed, including floor tracks, overhead trolleys riding on wheels or balls in channels incorporated within the ceiling, and folding door systems have also been used. In general, the appearance and performance of these movable panels have only been satisfactory in structures having plumb walls and ceiling that are substantially parallel to the floors.

Haws U.S. Pat. No. 2,945,535 describes a foldable partition system employing a relatively complicated overhead trolley support system wherein the panels are sealed at both top and bottom during installation by hydraulic cylinders pushing the track support system down into contact with the upper sealing strip of the panels. In such installations, a rather bulky decorated housing structure is extended downward below the ceilmg.

Stein U.S. Pat. No. 3,253,552 is'concerned mainly with improved trolley systems for movable wall panels and these panels are composed of two sections. For installation, the relatively shallow bottom section is extended downward from its recess in the lower end of the main body section by means ofa single scissors type jack. After the sealing strip beneath the bottom section reaches the floor, further operation of the jack elevates the main body section until the sealing strip on top thereof engages either the overhead track or the ceiling and the trolleys no longer support the weight of the panel. There is no provision for compensating for deflections in the ceiling.

The disclosure in Burmeister U.S. Pat. No. 3,072,975 resembles that of Stein except for employing crank arrangements as the panel elevating mechanisms.

Little attention has evidently been paid to the problems encountered with nominally flat ceilings that actually have pronounced deflection curves of either a relatively permanent nature as, for example, when the floor above is employed as a warehouse or a temporary dynamic deflection as may result from the changing loads occasioned by the use of the floor above as a parking garage.

SUMMARY OF THE INVENTION The present invention relates to a movable wall panel suspended from two overhead hangers which comprises a body having separate compartments adjacent to the top and bottom thereof and open at the top and bottom, respectively, a bottom casing telescopically mounted in said bottom compartment on a device operable to retract said bottom casing within said compartment prior to moving said panel or to extend said bottom casing below said bottom compartment into engagement with the floor to close the space between said bottom compartment and the floor and to elevate said body during the installation of said panel in a selected location, and a top casing telescopically and resiliently mounted in said top compartment to engage and conform with the contours of a surface thereabove to close the space between said top compartment and said surface when said body is elevated in installing said panel.

Narrower aspects of the invention are concerned with the combination with the foregoing panels of one or more of such features as employing two similar jacks operated simultaneously by a single actuating means to retract or extend said bottom casing, connecting the jacks to the body in a manner that permits longitudinal tilting of the bottom casing, the use of scissors jacks and specified attachments, utilizing a pair of springs under moderate compression as the resilient mounting for the top casing, equipping the overhead hanger with a safety cable disposed in a longitudinal channel through the hanger, providing stop fittings fastened to the cable adjacent to each end of the channel, disposing acoustic insulation between metal walls of the panel body and disposing strips of resilient material on top of the top casing and on the bottom of the bottom casing as effective seals against sound, light and air flow. A number of significant benefits and advantages are obtained with the novel structural features in the panels of this invention; and a description of these follows the detailed description of the panels.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional elevation (partially schematic) of a movable wall panel in the retracted condition and supported from an overhead trolley system.

FIG. 2 is a vertical cross section taken along the line 22 in FIG. 1.

FIG. 3 is an enlarged horizontal cross section taken along the line 3-3 in FIG. 2.

FIG. 4 is a side elevation view illustrating the manner in which the wall panels are placed in position.

FIG. 5 is an enlarged sectional detail of a portion of FIG. 1.

DESCRIPTION OF SPECIFIC EMBODIMENTS The movable wall panels of this invention may be conveniently suspended from a spaced pair of trolleys so that they can be easily guided to the desired location along suitable overhead tracks which may be embedded deeply or flush with the ceiling or supported on brackets below the ceiling. Each of the panels is comprises of at least three distinct sections, a central section or main body of the panel and two telescoping casings or sections that are mounted in compartments or recesses in the body. The upper casing is resiliently mounted on springs to project a predetermined distance beyond the main body, and this mounting allows it to telescope at least partially into the upper body compartment when the top casing or section engages the track or ceiling. The bottom casing is attached to a twin jack operating mechanism so that it can be retracted into the lower body compartment when a panel is to be moved or extended below the bottom of the main panel to serve as a bottom closure.

After the wall panel has been shifted to a selected location by the operator pushing it along the track with the bottom section retracted in order to clear the floor, the operator then extends the bottom casing downward by actuating its operating mechanism first until that casing reaches the floor and then to raise the entire panel until the top casing bears firmly against the ceiling. The trolley system is so designed that the wall panel can freely move upwardly for that purpose and the weight of the installed panel is no longer supported by the trolley as the hanger studs are lifted somewhat above their normal position so that the panel is supported entirely by the floor on which it rests.

This upward movement is started after the panel has been placed into edgewise engagement with a similar panel or perhaps a grooved member or groove in a permanent wall.

A movable wall panel is shown in FIGS. 1 and 2 in its retracted mobile condition in which it is suspended from a pair of overhead trolleys l1 and 12. This panel is an assemblage of a central section or body 13 and two telescoping top and bottom casings that can be at least partially housed in recesses in body 13. The resiliently mounted top casing 14 projects above the body 13 and is adapted to engage the overhead track to close off the space above the body and also to aid in firmly securing the panel installation in place. The retractable bottom section 15 is designed to be extended from within body 13 to fix the panel in position and close off the space beneath the body 13 and also to raise the sections 13 and 14 of the panel until the top casing 14 is in firm contact with the track and forms a seal there. The bottom casing 15 is retracted until it is entirely within a lower part of the body section 13 when it is desired to move the panel from one installed position to another location, and that retraction also disengages the top casing 14 from the ceiling and shifts the weight of the panel to the trolleys as will be described hereinafter.

The wall panel is usually a welded sheet metal struc' ture which includes a pair of spaced outer walls 16 and 17 having their vertical edges bent inwardly at right angles to form flanges l8, 19, 20 and 21 as illustrated in FIG. 3. Vertical channel members 22, 23 are secured between the outer walls 16 and 17; and channels 22 and 23 do not extend into the top and bottom compartments, instead they terminate short of the channels 25 and 28 described hereinafter. Depending on the width of the panel, one or more channels (not shown) of the same length and parallel to channels 22 and 23 may be spot welded to walls 16 and 17 for the purpose of stiffening the panel. The vertical edges of each panel are designed for tongue and groove engagement with adjacent wall panels. Thus, a channel 26 of blunt V-shape in cross section may be constructed from sheet metal or other suitable material, and secured to the inner surface of flanges l8 and 19 to provide the outwardly extending tongue projection. A slightly larger V-shaped channel 27 which may be constructed from perforated or solid sheet material is secured in the inner surfaces of flanges 20 and 21 and extends inwardly therefrom to provide the vertical groove along the opposite edge of the wall panel.

The compartment at the upper end of the body 13 is bounded mainly by an upper channel member 28 secured between the outer walls 16 and 17 with the flange portions of the channel member extending upwardly to the top edges of the outer walls; and its end walls are continuations of tongue channel 26 and groove channel 27, but the spacing channel members 22 and 23 are not employed in this top compartment section of the panel body 13.

The top casing 14 is an inverted channel member 29 which projects out of the upper end of the body 13. The ends of casing 14 are closed by securing suitable tongue and groove channels 30 and 31, respectively to the ends of channel 29. The external dimentions of this top casing 14 are slightly smaller than the internal dimensions of the top compartment, and channel 29 is slidably mounted within the channel 28 which has a polytetrafluoroethylene tape or coating 32 on the upper half of its surface to facilitate the sides of channel 29 sliding into channel 28 freely when the rubber sealing strip 33 is pushed into flrm engagement with any ceiling structure, such as the box track 34. To properly distribute the weight of the wall panel, rigid supporting plates 24 of metal (e.g. 3.5 inches X 5 inches) are secured to the lower surface of channel 28. The casing 14 is resiliently mounted on a pair of coil springs 35, each surrounding a trolley hanger stud 36 and located near an end of channel 28, which springs are mounted on a large spring-retaining washers 37 which rest on the bottom of channel 28 and are fastened to the plate 24 by machine screws. These springs also bear against the spring-retaining washers 37 which are fastened to the under side of the horizontal section of channel 29.

Springs 35 are adjusted in known manner to a controlled degree of compression by means of threaded flttings 38 at each end of the three flexible, stranded, restraining wires 39 surrounding each spring.

Near the bottom of body 13 is an inverted lower horizontal channel 25 with its flanges thereof extending downwardly and securely attached to the outer walls 16 and 17. Channel member 25 is positioned a suitable distance above the lower edges of the outer walls so as to provide a recess or bottom compartment within the body 13 for housing the schematically shown twin jack mechanisms 40 and 41 as well as bottom casing 15 when in the retracted position as shown in FIGS. 1 and 2.

Bottom casing 15 is essentially a channel member 42 with relatively long upwardly extending flanges, and its ends are closed by securing suitable tongue and groove channels 43 and 44, respectively, to the ends of channel 42 which has a laminated rubber sealing strip 45 on its lower exterior surface conforming to the shape of channels 43 and 44. The external width and length of bottom casing 15 are slightly smaller than the internal dimensions of body 13 so that the casing can easily be telescoped into the body of the panel. Either or both of the top casing 14 and the bottom casing 15 may be built larger for telescoping around the exterior of the upper and lower portions of body 13 rather than nesting into internal compartments of the panel, but such arrangements are usually less desirable from standpoints of appearance and possible damage in exposing more of the moving parts.

The operating mechanism is a combination of the bodies of two conventional screw-operated scissor jacks 40 and 41 arranged in tandem for simultaneous operation and each includes a generally horizontal threaded screw shaft 46 of special construction and a pair ofjack platforms 47 and 48 positioned, respectively, above and below the threaded shaft. This twin jack arrangement produces a very stable wall panel installation.

The operating mechanism for raising and lowering the bottom casing is connected to the body 13 of the panel in a unique and flexible manner to permit the bottom of channel 42 to be tilted up or down a small distance of perhaps one-half inch at either endfThis flexibility permits the jacks and the bottom casing to adapt to a slightly tilted suspension of the panel by the two trolleys and also to uneven or sloping floors. The bottom casing 15 is attached to the lower jack platform 48 by means of the shoulder bolts or screws 49 extending through the slots 50 in the bottom of channel 42 into threaded engagement with tapped holes in the lower platforms 48 of the jacks. These shoulder bolts permit platforms 48 to slide back and forth on the horizontal inner surface of channel 42 within the limits imposed by the length of the slots, and this freedom of motion is desirably improved by affixing polytetrafluoroethylene coatings or tapes on those surfaces of platforms 48 and channel 42 which are in contact with one another. The upper platforms 47 of the jacks are each rigidly attached by means ofa two machine screws (not shown) to holes tapped in a structural member in the form of a rectangular tubing or a box channel 51 having a wall thickness of approximately one-fourth inch. This bottom section structure, including the connection between the jack which is described hereinafter, may conveniently be prefabricated as a subassembly which is then inserted and connected with the body 13 of the panel.

The box channel 51 is attached to the body in a secure manner which nevertheless permits the aforementioned swinging or tilting motion of the box channel and all elements of the bottom section beneath it. This is accomplished by attaching the box channel 51 by means of two bolts 52 to a load distributing element in the form of the rigid metal plate 53 which is welded to the upper surface of the channel member 25. The two bolts 52, spaced only two or three inches apart, are the only connection between the box channel and the load distributing plate above it; and while these bolts are securely fastened in tapped holes in plate 53, the manner of connecting the bolts to the box channel provides the flexibility described earlier. The bolts 52 carry pipe collars 54 that are slightly longer than the depth of box channel 51 (e.g., l/32 to 1/16 inch longer for a 3 inch box channel). These pipe collars serve as spacers along with the relatively thick washers 55 (e.g., 1/8 inch thick) and thus permit the bolts 52 to be securely tightened without similarly restraining box channel 51 against all movement. In addition, a deliberately loose fit of the collars 54 in the holes 56 in the box channel is provided to promote flexibility in the mounting of the bottom casing 15. For example, the diameter of the holes 56 is desirably of the order of US to l/4 inch greater than the outer diameter of the collars 54.

In addition to the conventional bodies and elevating linkages, the twin jack simultaneous operating system illustrated in FIG. 1 consists of a hardened hexagonal bar 57 extending from the vicinity of the overlapping slots 58 and 59 in grooved channels 27 and 44, respectively, to its welded connection with the unthreaded end of the screw shaft 46 which raises and lowers jack 40; and the other end of shaft 46 is connected to the jack 41 through universal joint 60 having one arm welded to the threaded end of that screw shaft and its other arm welded to a square bar 61 which is slidably fitted into the square broach 62 to provide an expansion coupling, and a second universal joint 63 which has one arm welded to the end of broach 62 and the other arm welded to the screw shaft 46 ofjack 41. This drive train for simultaneous operation of the connected operating screw shafts 46 of the two jacks is actuated by extending a conventional socket wrench through the slots 58 and 59 and rotating the hexagonal bar 57 which is sized to fit such a wrench. The distance between jack platforms 47 and 48 is increased by rotating screw shafts 46 in one direction thereby pushing bottom casing 15 downward out of its recess, and the easing is retracted by rotation of these shafts in the opposite direction.

The screw shafts 46 of these jacks are also of unique design in having two extra bushings besides the conventional single bushing 64 affixed to the shaft 46 and which bears against ball thrust bearing 88 and the unthreaded trunnion 65 when the jack is being extended. The extra bushing 66 is welded to the shaft 46 on the other side of that trunnion, and it bears against thrust bearing 89 and the unthreaded trunnion when reverse rotation of the screw shaft 46 is being used to retract the jack. Bushing 66 provides for complete and positive retraction without the nuisance of applying pressure between the jack platforms as is necessary for the complete closure of a conventional scissors jack. Thus bushing 64 may be described as an elevation drive bushing and bushing 66 as a retraction drive bushing. The other extra bushing 67 is welded onto the threaded portion of shaft 46 in a predetermined location to serve as a stop which strikes the threaded trunnion 68 and halts further rotation of shaft 46 and thus limits the degree to which the jack can be extended. This prevents the panel from being raised-so high that the top casing 14 is telescoped so greatly as to have little available range of movement to compensate for downward deflection of the ceiling.

The sheet metal shell of the body. 13 is bounded by the side walls 16 and 17 and the channels 23, 25, 26 and 28, and this internal space is usuallyfilled with a suitable acoustic fibrous material selected for the thermal insulating and sound absorbing requirements of the particular installation. In general, fiber glass mat is very satisfactory for such purpose, and it is also desirable to fill the top body compartment between channel 28 and casing 14 and the bottom compartment between channel 25 and casing 15 with the same material.

It is generally preferable to build relatively narrow and stable movable panels as exemplified by a width of five feet for convenience in handling, shipping and storage as well as providing a better fit against sagging ceilings and uneven floors. Panel height is of course dictated by ceiling height and this sometimes exceeds 40 feet. In the case of such extremely tall panels, it is contemplated that the central body section between the channels 25 and 28 may desirably consist of several smaller units of l2 to 18 feet in height (or less if necessary) that can be easily shipped and carried through restricted passageways for assembly as a tall panel at the installation site.

Each trolley 11 and 12 supporting an end of the wall panel includes a circular bearing plate 69 and a plurality of spherical bearing members 70 individually housed in the bearing retainers 71 which contain a suitable lubricant for the bearings as well as a wiper seal (not shown) to prevent the entry of foreign matter.

The spherical bearing members support the bearing plate and trolley on a suitable overhead track which can be an almost completely enclosed box channel 34 shown in FIG. 2 with a longitudinal opening or slot 72 running along the entire length of its lower surface to provide for the movement of hangers 36. This box track 34 may be fabricated from a single piece of steel plate, and it may be secured to a ceiling with suitable bolts or brackets for mounting a track flush, in the ceiling or below the ceiling.

When the bottom casing is retracted into its compartment in the panel body 13, the weight of the movable panel is suspended from the long stud hangers 36 which transfer the load to the centers of the two bearing plates 69. Each stud 36 extends downward through slot 72 and apertures in the sealing strip 33, the top of channel 29 and the bottom of channel 28 where its thread 73 engages the thread in a tapped hole in the rigid plate 24. Thus, the stud is rigidly attached to the load bearing plate 24 and this connection is secured against loosening by means of the jam nut 74 and its lock washer on top of the plate as well as the retainer snap ring 75 which fits into a circumferential groove (not shown) in stud 36 below the plate 24.

At its upper end, the stud 36 extends through a hole 76 in the bearing plate 69, and this aperture is about 1/16 inch larger in diameter than the stud in order to permit a small amount of tilting of the stud without similar tilting of the spherical bearing member assembly. A thrust bearing assembly 77 consisting of two hardened steel washers, one above and one below a roller thrust bearing, is located on the stud immediately above the bearing plate 69. There is a slotted nut 78 engaging the threaded upper end of stud 36, and this nut is locked in place by the semi-circular spring 79 which has tab ends bent inwardly toward one another. These tab ends extend through the slot in nut 78 and into opposite ends of a hole drilled diametrically through the stud. At least one other such hole 80 is drilled through the stud at a different level in order to provide for adjusting the distance between the top of the panel and the overhead track. in particular, it is usually desirable to tilt the tongue edge of the panel slightly backward from its bottom corner to facilitate engaging it with the groove in the adjacent wall panel. This tilting can be readily accomplished by adjusting the nut 78 on the stud near the tongue edge 26 of the panel and locking spring 79 into the lower hole as in FIG. 2 while the nut on the remote stud is locked with the spring at the upper hole 80.

From an appearance standpoint, the studs 36 are desirably of the smallest diameter consistent with safety in order that the slot 72 and the overall size of the box track 34 may be as small and inconspicuous as possible. On the other hand, the stud 36 may be subjected to an extreme impact or bending moment in some installations if the wall panels are handled carelessly or roughly when being moved. The studs are typically of the order of 17 inches in length and they may be subjected to tremendous forces, as for instance, in the case of a panel about 36 feet long and weighing about 2000 pounds being pushed rapidly into an ell or tee intersection so that the foremost long stud hanger strikes the edge of the cross track with a great impact. Accordingly, it is desirable to provide a fail-safe type of stud which is novel and peculiarly adapted for use in the long stud hangers in the panels of the present invention.

One of these safety studs 36 is illustrated in FIG. 2 and it incorporates a inch diameter flexible stainless steel wire 81 of 7 X 19 standard construction disposed in a 3/l6 inch diameter central longitudinal bore that extends through the entire length of the stud. The wire or cable 81 has swaged fittings of a dome shaped type 82 resting on the top end of the bore and a cylindrical collar or barrel 83 hanging about /4 inch below the lower end of the bore. Thus, the safety wire has an effective or free length about A. inch greater than that of the stud 36 so that the wire remains in an unstressed condition without any wear or fatigue effects as long as the stud is intact. However, in the event of the stud being fractured by any mishap, the collar 83 will be drawn up against the bottom of the stud and the safety cable 81 will take up the entire load which it can readily sustain in view of its great tensile strength and flexibility. The operator handling the panel will be aware of the breakage of the stud by reason of the flexing motion felt as he pushes or pulls the panel. Also, the sudden /4 inch sag in the position of an end of the door will warn him of the breakage of the stud. Such a safety device is of unusual importance when incorporated in a movable wall panel in substantially eliminating the risk of death or personal injury or extensive damage to nearby equipment from falling panels in view of'the fact that panels of great length are frequently employed in exhibitions, trade shows, etc. attended by large numbers of people and with many costly instruments and equip ment on display.

The manner in which the wall panels are installed in their proper positions is illustrated in FIG. 4 with respect to wall panels 84, and 86 which are shown prior, during and after installation, respectively. Panel 84 is in its mobile state as it is suspended from the pair of overhead trolleys with bottom casing 15 fully retracted. In this condition, the wall panel is guided along the overhead track to a desired position adjacent other wall panels such as 85 and 86.

Panel 85 is being installed and this is positioned adjacent a previously installed wall panel 86, whereupon the operator actuates the twin jack mechanisms by meansof a socket wrench or other suitable wrench. Mating engagement of long tongue edges with grooved edges is facilitated by having the tongue edge 26 tilted backward from the bottom, and first inserting the tongue into the lower end of the vertical groove 27. Such tilting may be readily accomplished prior to installation by adjusting the stud nuts 78 to raise the tongue edge of the panel above its grooved edge. In addition, before and while operating the jack mechanism, it is desirable for the operator to apply pressure to the lower portion of the panel 85 to hold the tongue of that panel in close abutting engagement with the lower end of the groove of adjacent panel 86. It should be noted that due to the flexible manner of mounting the jack mechanism in the body 13, the bottom casing will properly engage the floor. lnitial operation of the jacks has pushed the bottom casing 15 down into sealing engagement with the floor but the level of body 13 was not changed and there is still a gap above the panel 85. It should be noted from FIG. 1 that the twin jack arrangement is located slightly off center and nearer its own grooved edge. Thus, as the operation of jack mechanixm is continued to raise the body 13, the panel 85 tilts back to the vertical, that is toward the top of adjacent panel 86 as indicated by arrow 87, to thereby assure close abutting engagement between the panels at their upper ends. Further operation of the twin jack mechanism raises the body 13 and top casing 14, until the overhead track compresses top casing 14 into its compartment in the panel. After the sealing strip 33 reaches the overhead track telescoping of the top casing 14 into the recess provided by channel 28 commences with any further lifting of body 13 by the jacks. Accordingly, the panel installation is complete soon after such telescoping starts; typically, a firm installation is obtained with top casing 14 telescoped about two inches. As the body 13 and top casing 14 are raised to the levels illustrated in panel 86 the studs 36 move upwardly through the centers of their respective bearing plates 69 so that the weight of the wall panel is no longer supported by the trolleys.

Wall panel 86 is shown in the installed position with the wall panel engaging both the floor and the ceiling and it has already compensated for any permanent ceiling deflections by the resilient mounting which also permits a restricted degree of longitudinal tilting of the top casing. Any further variations in the ceiling height, either of a static or dynamic nature, are automatically compensated for by the further compression or extension of coil springs 35.

As previously mentioned, the wall panel is filled with fibrous material and thus provides excellent acoustic insulation. This effect is enhanced by rubber sealing strips 33 and 45 secured to the top and bottom, respec tively, of the wall panel to provide seals which prevent the flow of acoustic energy either above or below the wall panel. As may be seen in H6. 3, the tongue and groove fitting between adjacent panels provides a labyrinth path which restricts the flow of acoustic energy between adjacent panels. Also with channel member 27 perforated and backed by fibrous acoustic energy dynamic nature without loss of the acoustic seal or damage to panels from changing ceiling heights after installation of the panels. Within the designed compensation range of the panel, changing deflections of ceiling or support track do not restrict its mobility or its installation or its storage. Also, carpets or floor tile may be subsequently laid on a bare floor by merely temporarily moving installed wall panels, as no floor tracks are involved and the resiliently mounted top casings easily compensate for the thickness of such floor coverings. While ceiling deflections are usually of a curved rather than a linear nature, such curves tend to be quite long; therefore the flat tops of the five-foot wide panels provide close fits against the ceiling contours. A resilient sealing strip of suitable thickness located on top of the casing completes the formation of a good seal at the ceiling; consequently such seals effectively prevent any drafts or passage of light, and no significant amount of noise and other sounds are transmitted across the space above the panels.

The overhead suspension system is designed to permit the use of the deflection-compensating top casing and the bottom casing is designed for a moderate degree of longitudinal tilting. Such tilting may be employed with suitable adjustment of the overhead hangers to facilitate the fitting or engagement of the tongue edge of the panel with the grooved edge of the adjacent panel; also, it enables the bottom casing to adapt itself to uneven floor contours. The use of two or more jacks provides a very desirable increase in the stability of the installed panel over that obtainable with a single jack. In addition, this permits using jacks of lesser width than would be required for a single jack and that is helpful in keeping the thickness of the panel as small as possible; moreover, it allows one to use jack bodies of common commercial size instead of ordering a special custommade jack for heavy panels. The provision of a stop bushing on at least one of the jacks at a predetermined location for a particular installation allows the panel to be installed rapidly by preventing it from being raised too high and thus restricting and designed range of compensation for ceiling deflections. Also, the addition of a retraction drive bushing to each jack facilitates the full retraction of the bottom casing by the jacks.

Finally, the use of fail-safe bolts or studs with internal safety cables is particularly desirable for the long hanger studs required for the deflection-compensating mounting of the top casing, particularly where such studs may be subjected to extreme impact or bending moments from the accidential or careless handling of panels as tall as twenty feet or higher.

Although the present invention has been described in great detail in respect to one embodiment of the invention for the purpose of providing a complete disclosure, it will be apparent to those skilled in the art that many other embodiements and modifications are within the purview of the invention. For example, synthetic resins, and especially those reinforced with glass and other fibers, may be substituted for many of the steel structural elements which are generally preferred. Accordingly, this invention should not be construed as limited in any particulars except as may be recited in the appended claims or required by the prior art.

I claim:

l. A wall panel which may be moved along tracks in a ceiling for selective division of a room comprising:

a ceiling for selective division of a room as described in claim 1 wherein the hanging means comprises:

A. a main panel member having top and bottom compartments constructed therein, said panel member having means for slidably hanging said main panel in the ceiling tracks;

B. a top panel section slidably mounted in telescopic 5 relation within the top compartments to form a top end surface for the main panel member; said top section being spring biased for retractable projection from said top compartment;

C. a bottom panel section slidably mounted in telescopic relation within the bottom compartment to form a bottom end surface for the main panel member, said bottom section being mounted on two or more horizontally spaced jacks for selective projection from said bottom compartment said jacks being secured to the main panel member; and

D. means in the bottom and top sections in operative association with the hanging means and the jack mounting means for allowing uneven projection of said sections in order to allow the bottom and top surfaces thereof to conform to ceiling and floors which are untrue.

2. A wall panel which may be moved along tracks in 12 a ceiling for selective division of a room as described in claim 2 wherein the top panel section is slidably mounted on the studs, said studs having coil springs mounted thereon to bias said top panel section in the projected direction.

4. A wall panel which may be moved along tracks in a ceiling' for selective division of a room as described in claim 3 wherein the openings in the top panel section through which the studs pass are oversized to provide the means for allowing uneven projection of said top panel.

5. A wall panel which may be moved along tracks in a ceiling for selective division of a room as described in claim 1 wherein the means for securing the jacks to the bottom panel section comprises:

A. threaded bolt elements secured to the jacks;

B. a load distributing element secured to the main panel member having tapped holes therein to receive the bolts; and

C. a channel member having passages therein through which the bolts may pass and being situated between the jacks and the main panel member, said passages being oversized to accommodate the bolts in a loose fitting manner to allow movement of said channel member.

6. A wall panel which may be moved along tracks in a ceiling for selective division of a room as described in claim 5 wherein the bottom panel section is mounted on the jacks by means of bolts which extend through slots in the bottom panel section, said slots providing a range of sliding motion for said section, thereby providing the means for allowing uneven projection of the bottom panel section. 

1. A wall panel which may be moved along tracks in a ceiling for selective division of a room comprising: A. a main panel member having top and bottom compartments constructed therein, said panel member having means for slidably hanging said main panel in the ceiling tracks; B. a top panel section slidably mounted in telescopic relation within the top compartments to form a top end surface for the main panel member; said top section being spring biased for retractable projection from said top compartment; C. a bottom panel section slidably mounted in telescopic relation within the bottom compartment to form a bottom end surface for the main panel member, said bottom section being mounted on two or more horizontally spaced jacks for selective projection from said bottom compartment said jacks being secured to the main panel member; and D. means in the bottom and top sections in operative association with the hanging means and the jack mounting means for allowing uneven projection of said sections in order to allow the bottom and top surfaces thereof to conform to ceiling and floors which are untrue.
 2. A wall panel which may be moved along tracks in a ceiling for selective division of a room as described in claim 1 wherein the hanging means comprises: A. two or more ball bearing trolleys horizontally spaced along the top panel sections, said trolleys engaging the tracks in the ceiling in a translatable relation; and B. studs secured to the trolleys and extending downward through openings in the top section to the main panel section where they are secured to support said main panel section.
 3. A wall panel which may be moved along tracks in a ceiling for selective division of a room as described in claim 2 wherein the top panel section is slidably mounted on the studs, said studs having coil springs mounted thereon to bias said top panel section in the projected direction.
 4. A wall panel which may be moved along tracks in a ceiling for selective division of a room as described in claim 3 wherein the openings in the top panel section through which the studs pass are oversized to provide the means for allowing uneven projection of said top panel.
 5. A wall panel which may be moved along tracks in a ceiling for selective division of a room as described in claim 1 wherein the means for securing the jacks to the bottom panel section comprises: A. threaded bolt elements secured to the jacks; B. a load distributing element secured to the main panel member having tapped holes therein to receive the bolts; and C. a channel member having passages therein through which the bolts may pass and being situated between the jacks and the main panel member, said passages being oversized to accommodate the bolts in a loose fitting manner to allow movement of said channel member.
 6. A wall panel which may be moved along tracks in a ceiling for selective division of a room as described in claim 5 wherein the bottom panel section is mounted on the jacks by means of bolts which extend through slots in the bottom panel section, said slots providing a range of sliding motion for said section, thereby providing the means for allowing uneven projection of the bottom panel section. 